This gearmotor is a miniature (0.94" x 0.39" x 0.47"), high-quality, high-power motor with 30:1 metal gearbox, similar to Sanyo's popular 12 mm gearmotors. The gearbox has a long (0.365" or 9.27 mm), 3 mm-diameter D-shaped metal output shaft, and the brass faceplate has two mounting holes threaded for M1.6 screws (1.6 mm diameter, 0.35 mm thread pitch). It weighs approximately 0.35 oz (10 g). These tiny, high-quality motors are intended for use at 6V. In general, these kinds of motors can run at voltages above and below this nominal voltage, so they should comfortably operate in the 3 - 9V range. Lower voltages might not be practical, and higher voltages could start negatively affecting the life of the motor.
Specs
Gear ratio: 30:1
Free-run speed @ 6V: 1000 rpm
Free-run current @ 6V: 120 mA
Stall current @ 6V: 1600 mA
Stall torque @ 6V: 8 ozáin
Extended motor shaft?: No
Size: 24 x 10 x 12 mm
Weight: 0.34 oz
Shaft diameter: 3 mm